MDB pool configuration & EJB3

[jc7442]

With JBoss 4.0.3 with EJB3, I try to limit the number of concurrent threads using an MDB. The following jboss.xml does not work. Is there any new feature with EJB3 ?

<jboss>
 <enterprise-beans>
 <message-driven>
 <ejb-name>sample.MDB</ejb-name>
 <configuration-name>MyConfig2</configuration-name>
 </message-driven>
 </enterprise-beans>
 <container-configuration extends="Standard Message Driven Bean">
 <container-name>MyConfig2</container-name>
<container-pool-conf>
 <MinimumSize>1</MinimumSize>
 <MaximumSize>5</MaximumSize>
 <strictMaximumSize>true</strictMaximumSize>
 <strictTimeout>10000</strictTimeout>
 </container-pool-conf>
 </container-configuration>
</jboss>

[jc7442]

It seems that annotation:

@PoolClass(maxSize=2,value=StrictMaxPool.class)

solves the problem for my MDB. Is it possible to specify the same thing with XML ?

[bill.burke]

you can do annotation overrides in the

ejb3-interceptors-aop.xml

You have to pick the right "domain" though...apologies for the poor doco.

[jjklappenbach]

One way is presented in the test classes provided with the source distribution of JBoss 4.0.3SP1. The example uses annotations to configure the pool, but each annotation has its descriptor analog.

Look for the file StrictlyPooledMDB.java. The lines you will find of interest:

@PoolClass (value=org.jboss.ejb3.StrictMaxPool.class, maxSize=StrictlyPooledMDB.maxActiveCount, timeout=10000)

where StrictlyPooledMDB.maxActiveCount is an int defined in the class to establish the maximum number of threads.

Your milage may vary here, as setting maxSize to low values can result in JMS subsystems exceptions.

-jjk

[judge2005]

And in case anyone is wondering. This is how you do the same thing in jboss.xml:

<?xml version="1.0" encoding="UTF-8"?>
<jboss
 xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
 http://www.jboss.org/j2ee/schema/jboss_5_0.xsd"
 version="3.0">
 <security-domain>java:/jaas/example-domain</security-domain>
 <enterprise-beans>
 <message-driven>
 <ejb-name>sample.MDB</ejb-name>
 <pool-config>
 <pool-class>org.jboss.ejb3.StrictMaxPool</pool-class>
 <pool-max-size>1</pool-max-size>
 <pool-timeout>5000</pool-timeout>
 </pool-config>
 </message-driven>
 </enterprise-beans>
</jboss>

BTW thanks for this thread. You saved my bacon. And thanks to Eclipse for having an XML editor that understands xsd. Oh and thanks to JIRA for showing that the xsd existed!

Finally I'd like to thank my producer... j/k - its late.

[wolfc]

Before you get your hopes up out of old posts, note that pool configurations on a MDB is not the way to go. http://jira.jboss.com/jira/browse/EJBTHREE-890

Also note that expiration of messages is an issue. http://jira.jboss.com/jira/browse/EJBTHREE-938

[ejb3workshop]

I am having a problem following your suggestion. I increased by session size to 20 using :

@ActivationConfigProperty(propertyName = "maxSession", propertyValue = "20"

but now I get the following exception :

Failed to acquire the pool semaphore, strictTimeout=10000

A search on the forum suggestion that I need to increase my MDB pool size to boyond the number of the sessions.
http://www.jboss.org/index.html?module=bb&op=viewtopic&t=58293

However you suggest that this is not the way to go. I tried it and it didn't work. It complained about the jboss.xml file not being correct.

Is there another solution to the Failed to acquire the pool semaphore, strictTimeout=10000 ?

Thanks
Alex

[kaja78]

http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4135987